In order to achieve visual comfort and energy savings with the use of daylight, an accurate assessment is necessary in office spaces. One of the indicators used to assess the discomfort caused by high luminances in the field of view of the observer, is psychological glare. The aim of this study is to evaluate indoor workspaces in different glare conditions caused by the implementation of solar shading device (SSD), specifically indoor textile curtains, with different transmittance levels. The methodology used is based on daylight dynamic simulation through computer-aided design (CAD) and Daylight Glare Probabily (DGP). Results showed that the implementation of SSD significantly reduces the annual period of time with glare (less than 4%). The analysis of daylighting conditions through -DGP- is a fundamental tool in the design stage, which allows us to predict the luminous behavior of a space prior to construction, as well as for future in situ interventions.

This research investigates the effects of perceived indoor temperature on glare sensation. A laboratory experiment was carried out where volunteers (nº 19) performed an office-like computer task. Three scenarios with sunspots over thedesk were evaluated: a cold scenario, a comfort scenario and a hot scenario. All had the same vertical illuminance at the eye and luminance ratios. Discomfort glare was measured with the predictive daylight glare probability (DGP) model; actual perception of glare was assessed with glare sensation vote (GSV) scale; while thermal comfort was evaluated with thermal sensation vote (TSV) scale. In order to know how much the perceived temperature contributes to the model, an ordinal regression was performed. The result showed a Nagelkerke pseudo-R2=0.52, p=0.001, indicating that the perceived temperature affected glare predictions. This is an improvement in the understanding of daylight glare, which will allow researchers and practitioners to make informed decisions about sustainable design and occupant comfort. In conclusion, a more comprehensive glare model should include perceived temperature as a variable of the current glare model. Also, the results suggest that DGP should be used only when the person is in thermal comfort.

The daylight impact on the visual environment is fundamental on visual display terminal work (VDT). Visual performance and visual comfort should be considered for equal. The study (n=16) was performed at the experimental lighting laboratory. Office work with VDT was evaluated using STROOP task in two orientations: (with/without solar presence in the visual field). Our hypothesis states the existence of a relationship between ocular behavior and visual comfort of workers. An eye-tracker was employed in order to record the ocular gestural parameters: blinks, direction of gaze, eye aperture (Degree of eye?s openness) and pupil size, which were correlated with the vertical illuminance at the eye. Visual comfort was assessed with Glare Sensation Vote. Results indicate a strong negative linear correlation between eye illuminance and the degree of eye?s openness in the direct sunlight scenario (p=-0.636; s=0.008) and in diffuse light scenario (p=-0.661; s=0.005), that could be the main predictor of visual discomfort. This experiment allowed us to explore eye behavior patterns that could be visual comfort indices under glare risk situations.

This article studies the ocular behaviour of office workers in the presence of glare. Additionally, the study seeks to obtain a new indicator for glare prediction that compensates the inaccuracies of glare predicted by the existing models of glare sensation vote (GSV), daylight glare probability (DGP) and daylight glare index. A laboratory experiment was carried out (n=18) simulating an office space. The volunteers participated in four office tasks (reading from a screen and from a paper, writing and socializing). Two scenarios were evaluated: one with sunspots on the faces of the subjects and the other with sunspots on the working area. By means of a visible spectrum eye tracker these ocular parameters were registered: direction of gaze, the degree of opening of eye and pupil size. These ocular parameters were correlated with vertical illuminance at the eye. The results show that the degree of reduction of opening of the eye was the best predictor of visual discomfort with statistically significant differences between scenarios (p=?0.728, s =0.001). The other important predictor was the pupil size. The degree of opening of eye and pupil size was correlated with glare indices. The degree of eye opening has a good correlation with GSV and DGP and it could be a future index of visual comfort under situations of the risk of glare.